Mathematical Modelling of Multi-Region Spread of Epidemic

SAIR model of growth of an epidemic is extended to a system of many interacting regions. Interactions are described by exchange of populations between various regions. Differences caused by the exchange of susceptible population, in addition to infected individuals are noted. It is shown that initial phase of the epidemic is governed by a linear system. Analysis of linear system shows that a fundamental mode gets established that governs the spatial profile of the spread of the disease.